If you press and hold the stop/start button, it will shut off the engine first and then the auxiliary power. No need to press the button twice. I cannot comment on the unlocking because I do not have my doors set to auto lock. Maybe holding the button will unlock the doors as well? Give it a try and let us know.

This is true for some older models, apparently including the X1. On the more recently designed ones, like the F25 and F30, a long press does no more than a short press. But on those cars (as well as older models), once the engine is shut off, exiting the car and locking it will shut down the rest of the electricals, so the second press is, to that extent, not necessary.

As far as the door locks are concerned, there are a couple of solutions. The one I favor is to disable the auto-locking. Driving around with the doors locked serves no useful purpose that I can see. Another possible approach is to code the car's computer system to unlock the doors automatically when the car is shut off or put in Park or whatever. This can be done, apparently, and is a standard feature in some markets.

One last option: an impact strong enough to deploy airbags will also unlock the doors. So there's that . . . .